[hubbard]

tried 2 different loads with similar results. load 1 was a storebought 255 bbswc with 18gr./2400. load 2 was a 273 gr. ohaus swc sized to .454 with 18/2400. point of impact was a little different but group size was similar at 3.5 to 4 inches at 25 yds. this is comparable to 2 other 45 blackhawks from past years. my cylinder mouths measure .452 to .4525. bore size is . 4515 and area in front of forcing cone is .450. i've read the posts on borelapping over the last year but i haven't tried it. i understand about imbedding the grit in bullet surface and firing them at slow velocities. anyone have an idea about how many shots it may take to open up this constriction?

 

[The Blade]

John,

Jim Stroh at Alpha Precision has a technique for removing the thread choke that he calls Taylor Throating. I've had him do it to one of my Rugers, and it made a remarkable difference with cast bullets.

I'm currently firelapping a Vaquero in an attempt to remove a slight thread choke. I've fired 20 rounds so far, and it is working slowly. I expect that 50 rounds may remove my constriction, but it's not quite as tight as yours.

Beartooth Bullets sells a "Technical Manual" for $10-$12 that's a real good read on preparing handguns and rifles for cast bullet accuracy. The book covers firelapping in great detail. Even if you don't like the idea of firelapping, it's an interesting book for just a few bucks.

The Blade